Today's networked computing environments are used in businesses for generating and storing large amounts of critical data. For example, banks, insurance companies, and manufacturing companies generate and store critical data related to their business and to their customers. It is therefore very important that the storage systems used for storing the critical data are highly reliable. “High Availability” storage systems employ various means for optimizing the reliability of storage systems.
High Availability systems are generally designed such that single points of failure are avoided. One means for avoiding single points of failure is to provide redundant components. For example, two processors may be provided such that if one fails, the other can assume the role of the first processor as well as its own. However, redundancy is costly and can be an inefficient use of resources.
Furthermore, when designing Highly Available systems, the failure of a component in the system can cause redundant parts of the system to fail as well. Special care must be taken to ensure that component failures do not cause cascading failures.
What is needed is a High Availability storage system that employs mechanisms for avoiding single points of failure efficiently and effectively.